Ceanothus cordulatus |
Ceanothus fendleri |
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mountain whitethorn, snow bush, whitethorn ceanothus |
Fendler buckbrush, Fendler's ceanothus |
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Habit | Shrubs, evergreen, 0.5–1.5 m. Stems ascending to spreading, not rooting at nodes; branchlets yellowish or grayish green, glaucescent, thorn-tipped, round in cross section, rigid, puberulent, glabrescent. | Shrubs, evergreen, 0.5–1.5 m. Stems erect, ascending, or spreading, rooting at proximal nodes; branchlets green to grayish green, thorn-tipped, round in cross section, rigid, canescent, often glaucous. |
Leaves | petiole 2–8 mm; blade flat to cupped, ovate to elliptic, 10–30 × 6–18 mm, base rounded, margins usually entire, sometimes minutely glandular-denticulate distally, glands 18–30, apex obtuse, abaxial surface pale grayish green, sparsely puberulent or glabrous, sometimes villosulous along veins, adaxial surface pale green to grayish green, glaucous, dull, glabrate; 3-veined from base. |
petiole 1–4 mm; blade flat, elliptic, ovate, or orbiculate, 8–25(–30) × 3–8(–14) mm, base cuneate to rounded, margins usually entire, rarely serrulate near apex, teeth 3–7, apex obtuse to rounded, abaxial surface pale green or grayish green and glaucous, appressed-villosulous to tomentulose, especially along veins, adaxial surface dark green, dull, appressed-villosulous or glabrous; 3-veined from base (lateral veins sometimes obscure). |
Inflorescences | axillary, umbel-like or racemelike, sometimes densely clustered, 1.2–2(–4) cm. |
terminal or axillary, usually umbel-like, sometimes racemelike, 1–3.5 cm. |
Flowers | sepals, petals, and nectary usually white, rarely pink. |
sepals, petals, and nectary white or pinkish. |
Capsules | 3.5–5 mm wide, lobed; valves rugose, viscid when young, weakly crested. |
4–6 mm wide, lobed; valves smooth to rugose, viscid, usually not crested, sometimes weakly crested. |
2n | = 24. |
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Ceanothus cordulatus |
Ceanothus fendleri |
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Phenology | Flowering May–Jul. | Flowering Jan–Jul. |
Habitat | Rocky ridges and slopes, chaparral, conifer and mixed evergreen forests. | Rocky soils, slopes, open sites, chaparral, oak-pine woodlands, conifer forests. |
Elevation | 400–3400 m. (1300–11200 ft.) | 1400–2700 m. (4600–8900 ft.) |
Distribution |
CA; NV; OR; Mexico (Baja California)
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AZ; CO; NM; SD; TX; UT; WY; Mexico (Chihuahua, Coahuila, Sonora)
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Discussion | Ceanothus cordulatus is one of the most common shrubs in montane chaparral and forests of the Coast Ranges and Cascades of southern Oregon and northern California, southward through the Sierra Nevada, Transverse and Peninsular ranges of California, to the mountains of northern Baja California, and occurs disjunctly in the Charleston Mountains of Nevada. Putative hybrids between Ceanothus cordulatus and C. velutinus var. velutinus, reported from the Klamath Mountains, the southern Cascade Range, and the Sierra Nevada, have been called C. ×lorenzenii (Jepson) McMinn. A rare intersectional hybrid between C. cordulatus and C. prostratus in the Lake Tahoe basin has been named C. ×serrulatus McMinn. Putative hybrids of C. cordulatus with C. diversifolius and C. integerrimus also have been reported (H. McMinn 1944). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Plants of Ceanothus fendleri with glabrous leaves found throughout its range have been called var. viridis. The name C. fendleri var. venosus has been applied to plants with widely elliptic, villosulous leaf blades. Such plants are similar to C. buxifolius of northern Mexico (Chihuahua and Sonora), which has glabrous or sparsely puberulent leaf blades and ± persistent glands on denticulate leaf margins. Putative hybrids between C. fendleri and C. herbaceus in the eastern foothills of the Rocky Mountains were named C. ×subsericeus Rydberg. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 87. | FNA vol. 12, p. 87. |
Parent taxa | Rhamnaceae > Ceanothus > subg. Ceanothus | Rhamnaceae > Ceanothus > subg. Ceanothus |
Sibling taxa | ||
Synonyms | C. fendleri var. venosus, C. fendleri var. viridis | |
Name authority | Kellogg: Proc. Calif. Acad. Sci. 2: 124, fig. 39. (1863) | A. Gray: Mem. Amer. Acad. Arts, n. s. 4: 29. (1849) |
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